I've already set up a Twitter account a while back, but never warmed up with it and probably never really will. But Twitter is more than just a tool to play. It's on it's way to become mainstream.
I personally don't really need to post mynonsense on Twitter, but I'd like to do it for "research" and analyze how this tool might be useful.

What especially interests me is how much and what kind of traffic Twitter generates. I also wonder how the integration with a mobile device and Gtalk/AIM / Facebook / Friendfeed effects how people consume the web. Also how does a blog be effected by Twitter if my Tweets show up as a blog posting (curently I still have it off until I am more comfortable with posting Tweets here).